Carburizing box



P. A. E. ARMSTRONG.

CARBURIZING BOX. APPLICATION FILED JAN.30,19 20.

Patented Feb. 21, 1922.

ATTORNEY spar cares.

CARBURIZING BOX.

orass.

Specification of Letters Patent.

Patented Feb. 211, 11922.

Application filed January 30, 1920. Serial No. 355,290.

To all whom it may concern:

Be it known that I, PERCY A. E. ARM- STRONG, a subject of the Kin of Great Britain, and a resident of udonvllle, county of Albany, State of New York, have invented certain new and useful Improvements in Carburizing Boxes, of which the following is a specification.

My invention relates to carburizing boxes, heating pots and the like.

An object of the invention is the provision of a box or pot and a lid therefor which can be readily and quickly made tight with refractory material, such as clay, sand, and the like.

Another object is the provision of the bottom of the box or pot with runners, making it easy to move same about and into and out of the furnace, and preventing scraping or cutting of the furnace bottom.

In the drawings, Fig. 1 is a side view, partly broken away, of one form of box embodying my invention and luted with clay or the like material. Fig. 2 is an end view of the box shown in Fig. 1, partly in section. Fig. 3 is an enlarged sectional detail of a modification, and Fig. 4 is an enlarged detail view illustrating the use of sand or like material for making the lid tight.

The boxes or pots may be of various sizes and shapes, as rectangular, cylindrical, etc. In the form shown have illustrated a rectangular box 10 about as high as wide and about twice as long as wide.

The box or pot is preferably made as a casting. Stable surface alloy steel, as described in my Patent No. 1,322,511, issued November 25th, 1919, is well adapted for making these boxes and pots. Such alloy steel, well adapted for this purpose, may contain (by weight) chromium about 8.0% to 30.0%, silicon about .5% to 5.0%, carbon about .05 to about 1.0%, and the principal part of the remainder iron. The following is one particular analysis which gives very satisfactory results:

Chromium 12.0 Silicon 4.5 Carbon .60% Manganese .30% Phosphorus .03% Sulphur 03% Iron The remainder So far as the form of the box is concerned,

however, any suitable metallic material ma be used which is adapted to stand up wel under the temperatures to which it is subjected.

The box 10 is preferably provided with runners 11, 11 cast integral therewith. These runners are preferably curved about as shown in Fig. 1. Two runners, one at each side, are shown, but more runners may be used and they may be arranged in various ways.

The box i preferably provided about the top with a channel for receiving the downwardly projecting marginal flange of the 11d or cover.

. In the form shown in Figs. 1, 2 and 4, the channel 12 is provided on the outside of thebox by forming a flange 13 thereon, comprising a portion 14 extending outwardly therefrom a short distance below the upper edge of the box wall 15, and a portlon 16 extending upwardly and preferably ontwardly from the base portion 14. The cover 17 has a depending marginal flange portion 18 adapted to be received within the channel 12 ,and extending preferably to near the bottom of channel 12. Said cover 17 may also have an upwardly extending flange 19 'set back somewhat from the edges thereof to provide room between flanges 16 and 19 for a substantial packing of clay or other closure forming material.

With this construction the flange 18 of lid 17 enters the channel 12 and the under side of lid 18 rests directly on the upper edges 15 of the box walls, and an open space or groove 20 is left all around the cover Within the flange 16 for receiving a luting of fire clay or similar plastic material as indicated at 21 in Figs. 1 and 2. Instead of using plastic material, dry refractory material, such as sand may be used to fill the recess or groove 20 as indicated at 22, Fig. 4. The sand will fill the groove entirely to the bottom thereof and may extend upwardly somewhat into the clearance space 23 between fiange 13 and box walls-15,.but cannot enter the interior of the box or pot because the box walls extend bottom of channel 12. The plastic material will ordinarily not enter so far as the sand, but may obviously be forced into space 23, if desired. With lids 17 fitting fairly closely the clearance space 23 will be reduced somewhat, but in any case the lid is so. conupwardly above the structed that it-may be readily put on and In the modified form of Fig. 3 the flange 13' extends outwardly and upwardly from about the top of wall15 and the lid 17 has only the upwardly extending flange 19', the flange 18 being dispensed with, and the clay or other luting or closing material is introduced into the oove 20'. Material such as clay is prefera ly used with such boxes or pots, as sand. or the like material might get into the box under the lid. In both cases, however, it will'be seen that the hollow interior of the box is smooth and square at the top, corners about the inner side of the lid, so that the entrance and removal of objects to be carburized and carburizing material is not interfered with in any way.

In Fig. 1, I have shown the box 10 filled with carburizing material 24, in which are placed articles 25 to be treated. The boxes, pots, etc., may be used for other purposes, as for annealing, etc.

It will be seen that boxes constructed as described can be tightly and effectively sealed in a very simple and easy manner, that the clay or other sealing material, while easily removed when the box is to be opened, is not readily knocked or pushed outof place in use, and that the box walls can be held from spreading by the downwardly extending flanges on the lid. These boxes and pots can also be easily moved or pushed around on the runners without injury to the furnace or other floor on which they are placed. I claim:

1. A carburizing box or-the like, having a flange extending outwardly and upwardly from the walls of the box near the top edge thereof and providing a channel, and a lid adapted to rest on the top edge of said box and provided with a flange adapted to extend downwardly into said channel and near but not to the bottom thereof.

2. A carburizing box provided with an outwardly and upwardly extending flange,

and a lid having an inwardly and upwardlyextending flange, leaving a protected channel therebetween for the insertion of refractory closure material.

3. A carburizing box or the like, havin a flange projecting outwardly and upwardly from the walls of the box near the top thereof but below the upper edges of the walls and forming a channel about the walls, a lid having a downwardly projecting flange adapted to extend into said channel and also having an upwardly extending flange adapted with the flange onthe box to provide a protected groove for the reception of refractory closure material.

In testimony that I claim the foregoing I hereto set my hand, this 27th day of J anuary, 1920.

. PERCY A. E. ARMSTRONG. 

